A
funny thing happened to CPUs recently, some of them got a lot more power efficient
and a lot cooler. A few AMD Athlon and Phenom processors are pushing out as little as 80W, others as little as 65W or even
45W! Die shrinks are making mainstream and entry level processors much more energy efficient, and
substantially more affordable too. If you've recently built a PC system with one
of these energy efficient CPUs, you might be able to get away with a plain and compact heatsink that doesn't cost a whole lot.

You can
save a lot of money on the CPU heatsink if you know that a processor with a TDP (Thermal Design Power) of under 90W doesn't require a
$80 heatsink. In fact, if the CPU heat output is low, a dead simple extruded
aluminum heatsink will probably be sufficient. Take for example the heatsink Frostytech is
testing today; the Glacialtech Igloo 7312 Silent E.

The Igloo 7312 Silent E is a moderately compact AMD
K8 heatsink, made just of extruded aluminum and an 80mm fan. The Glacialtech
Igloo 7312 Silent E is rated for a maximum load of 89W, and is very
quiet. Glacialtech's Igloo 7312 Silent E heatsink stands just 70mm
tall and comes with a fixed speed 80mm fan
that rotates at a quiet 2000RPM. Weighing in at a
light 371 grams, the Igloo 7312 Silent E is compatible with AMD socket 754/939/940/AM2
processors of 89W TDP or less. Frostytech tested the heatsink
up to 125W, and the results weren't just satisfactory.

There's not a lot else that needs to be
said about the Glacialtech Igloo 7312 Silent E heatsink, other
than to reiterate that it's best suited to smaller enclosures where vertical height is restricted, and to energy efficient processors that don't run very hot.

Base Finish and Flatness

Flipping a heatsink over to inspect the business
end is often a simple indicator of overall cooler quality. More practically
speaking, a heatsink is in many ways only as effective as the contact it makes
with the processor - the flatter and smoother the better. Base finish is one of
the criteria that Frostytech measure in the course of evaluating heatsinks, and
it involves two distinct aspects. Surface Finish is the first; this is
calculated with the aid of Surface Roughness Comparator that has a cross section
of common machine surface finishes and their numerical surface roughness
equivalents in microinches. The second is Surface Flatness. This is tested with
an engineers straight edge or proven flat surface, in two axis.

The base of
the Glacialtech Igloo 7312 Silent E heatsink has
a surface roughness of ~32 microinches. The base is 77x40mm in size and generally
quite flat in both axis. A patch of good quality shin-etsu thermal compound is
pre-applied for easy installation.

FrostyTech's Test Methodologies are outlined in detail
here if you care to know what equipment is used, and the parameters under
which the tests are conducted. Now let's move forward and take a closer look at
this heatsink, its acoustic characteristics, and of course its performance in
the thermal tests!